110 kV Kidričevo – Ptuj – Formin transmission line modernization – implementation of superconductors

As part of the modernization of Slovenia’s power transmission network, the reconstruction of the 110 kV Kidričevo – Ptuj – Formin transmission line was carried out. This project is significant as it represents one of the first implementations of ACCC® (Aluminum Conductor Composite Core) conductors in Slovenia, enabling a substantial increase in power transmission capacity without replacing the existing towers.

The works were carried out in several phases. The total length of the reconstructed transmission line is 20.4 km, while a total of 62.37 km of ACCC® conductors was installed. This type of conductor, which uses a composite core instead of a steel core, provides significant benefits in terms of reduced losses and increased transmission efficiency.

• Transmission line voltage: 110 kV
• Total route length: 20.4 km
• Length of installed ACCC® conductor: 62.37 km
• Conductor type: HTLS (High-Temperature, Low-Sag) with composite core
• Replacement of conductors while retaining existing concrete towers
• Increased electric power transmission capacity

• Work on old Pi-type concrete towers, originally built in 1948.
• Conductor clearance was at the limit of permitted values, which was resolved by using ACCC® conductors that allow reduced sag and greater safety clearance.
• Licensing and specialized training of workers, as the manufacturer requires installers to be certified for the installation of this type of conductor.
• Integration with the existing network to ensure stable power transmission throughout the reconstruction process.

Our subsidiary ENS Slovenia was the key contractor on this project, including:

• Training and licensing of installers for ACCC® conductor installation.
• Removal of the old conductor and installation of the new ACCC® conductor.
• Optimization of conductor safety clearances to achieve higher transmission capacities.
• Testing and commissioning of the system, ensuring guaranteed performance of the new conductor.

• Increase in transmission capacity without replacing towers, reducing costs and implementation time.
• Reduction of power losses thanks to advanced conductor technology.
• Strengthening network stability by reducing tensile forces and maintaining appropriate protection angles, increasing overall transmission efficiency.
• Support for Slovenia’s sustainable development and energy transition strategy.
• The ACCC® conductor is not only faster – it is safer, more resilient, simpler, more reliable, and a more efficient method of power transmission.
• Opening opportunities for further application of ACCC® conductors in the region.

The modernization of the 110 kV Kidričevo – Ptuj – Formin transmission line represents a revolutionary step in Slovenia’s power sector, proving the effectiveness of superconducting solutions in upgrading existing networks without the need for extensive construction works. This project lays the foundation for the further implementation of similar technologies across the region.